Heat-sensitive copying device

ABSTRACT

Disclosed herein is an improved heat sensitive copying device operable to provide rapid, very short duration, light flashes from a flash lamp providing the heat necessary for accomplishing the copying operation. The rapid succession of flashes is enabled by the use of two condensers alternately coupled to the flash lamp and a charging circuit through a switching circuit. While a charged condenser is being discharged to light the lamp, the other condenser is being charged. When the condenser coupled to the lamp has discharged the switch means can reverse the condenser connections to couple the just charged condenser to the lamp.

[54] HEAT-SENSITIVE COPYING DEVICE [7 5] Inventors: Shinichi Yabe; Tomi Okada, both of Ashigara-Kamigun, Kanagawa, Japan [73] Assignee: Fuji Photo Fuim Co., Ltd.,

Kanagawa, Japan [22] Filed: July 8, 1971 21 Appl. No.: 160,666

[30] Foreign Application Priority Data July 8, 1970 Japan ..45/6828() [52] [1.8. CI. ..250/65 T, 315/241 P [51] Int. Cl.....G0ln 23/04, HOlj 37/22, HOSb 41/14 [58] Field of Search ..250/65 T; 315/241 P [56] References Cited UNITED STATES PATENTS 3,163,755 12/1964 Kotz et al ..250/65 T [111 3,737,662 1 June 5, i973 3,564,597 2/1971 Vrancken ..250/65 T Primary Examiner-James W. Lawrence Assistant Examiner-T. N. Grigsby Attorney- Richard C. Sughrue, Gideon Franklin Rothwell, John H. Mion [57] ABSTRACT Disclosed herein is an improved heat sensitive copying device operable to provide rapid, very short duration, light flashes from a flash lamp providing the heat necessary for accomplishing the copying operation. The rapid succession of flashes is enabled by the use of two condensers alternately coupled to the flash lamp and a charging circuit through a switching circuit. While a charged condenser is being discharged to light the lamp, the other condenser is being charged. When the condenser coupled to the lamp has discharged the switch means can reverse the condenser connections to couple the just charged condenser to the lamp.

1 Claim, 4 Drawing Figures HEAT-SENSITIVE COPYING DEVICE BACKGROUND OF THE INVENTION The present invention relates to a heat-sensitive copying device using infrared rays as the heat source.

In a copying device of this type, exposure for reproduction is generally provided by using a high power infrared lamp having a tungsten filament as a heat source and a reflecting mirror made of a good heat conducting metal plated or vacuum deposited with gold so that infrared rays from the lamp are reflected and focused. Because the irradiation by the high power infrared rays is continued for a definite period of time, the device must be cooled. Further, the device must be made of materials having a high heat-radiative property or high heat resistance. Besides these defects, there are many restrictions about structures and materials. Moreover, the heat sensitive copying paper increases in temperature as the exposure time increases. Therefore, the exposure time becomes irregular, and the temperature of the device must always be controlled. The device is also defective in that clearness and resolving power become low because of super heating.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive copying device which overcomes the above-mentioned defects and has such features as listed below.

1. Using a flash lamp as a light source and making flashing time thereof short.

2. Throwing off high power of infrared rays in ashort time.

3. Using heat generated by said throw of infrared rays.

4. Deleting the ordinary structural and material limitations.

5. Deleting the super heat of copying paper itself.

6. Obtaining a clear copy good in quality.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be made clear and concrete by the following explanation based-on drawings, in which FIG. 1 is a simple side view of a general embodiment of a heat recopying device.

FIG. 2 is a perspective view of an embodiment based on the present invention.

FIG. 3 is a circuit including a lamp in the device in FIG. 1.

FIG. 4 is a circuit including a lamp in the device in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a generally well known heat sensitive copying device is shown, into which original l'is'sent coupled to a heat sensitive copying paper 2 it is called a heat sensitive paper hereafter and they advance by being nipped between a backup roller 3 and a heat enduring transparent belt 4, during which time an infrared ray lamp 6 is lighted. Thelamp 6 is set at thecenter of a reflecting mirror plated with gold or covered with gold by evaporation thereof. The written part on the original 1 becomes high in temperature causing it to absorb infrared rays, revealing colors. As the infrared ray lamp 6 has been lighted during passage of the heat sensitive paper, the reflecting mirror 5 and the backup roller 3 are heated causing the temperature of the heat sensitive paper itself, which is conveyed in contact with the backup roller 3, to increase. Therefore, an unnecessary part of the heat sensitive paper colors are revealed, which causes the clearness and resolving power to be low. It has been very troublesome to control the speed of copying or the on time of the infrared rays, that is, the infrared throw and thus to control the speed of heat up and temperature of the device.

The present invention uses an Xe gas or He gas filled lamp 7 as the light source shown in FIG. 2, and a reflecting mirror 8 plated with gold or covered with gold by its evaporation to improve the efficiency of the infrared rays throw. But a throw of the flash lamp 7 is very short for example about one one-thousandth sec. so endurance against heat as generally needed, is not necessary. Even synthetic resin can endure the heat generated by lamp 7. By these reasons it becomes very easy to make a reflecting mirror having a smooth parabolic reflecting surface.

By the present invention, the infrared rays throw time is very short, and thus super heating of the heat sensitive paper does not occur. As a result a very clear copy is obtained.

The original 1 and the heat sensitive paper 2 are coupled and put on a cushion material 9, a transparent pressing plate 10 is used to bring the original 1 into deep contact with the heat sensitive paper. For a reflecting original, the position of the original 1 and the heat sensitive paper 2 is reversed. When an exposure button is pushed, the flash lamp 7 flashes and copying is accomplished. During the copying step, prior devices have such a defect that as shown in FIG. 3, in a lighting circuit including a flash lamp, when a switch S is shut a flash lamp V is triggered, the electric charge on a condenser C is discharged and the lamp V lights. However, the lamp V lights continuously and the condenser C must be charged anew which needs much time. Therefore, a prompt next exposure is impossible.

To delete this defect, the present invention has two condensers such as C and C in'FIG. 4, to store charge for light. By pushing an exposure button 8,, a relay R is energized, and a flip flop circuit FF is operated by a self contact point S causing output contact points S 8,, to switch. The pushing of button S simultaneously causes another self contact point S to close, energizing a delay relay R which shuts its self contact point S working a little later than a relay R The-flash lamp V is thus triggered and lights. When the is charged and when C is being discharged, C is charged. In this manner a prompt next copying becomes possible.

In addition, a clear copy, free from super heating, is obtained by the use of the present invention, in that first the original 1 and the heat sensitive paper 2 are coupled and inserted into the heat sensitive copying device, and'then, for a short timea flash lamp is lighted. When the copying finishes, after taking off the copied heat sensitive paper 2 and the original 1, the original 1 and another heat sensitive paper 2 are coupled again and inserted into the heat sensitive copying device, the

heat stored is discharged and super heating of the copy ing paper is prevented. That is to say, an intermittent conveyance of the heat sensitive paper and an instant synchronized flash of the lamp prevent super heating of the flash lamp and make it possible to obtain a clear copy.

As mentioned above, the present invention has the following effects.

First, by using a plurality of condensers, one being charged while the other is discharged, the necessary electric charge to light a flash lamp for heat sensitive copying is realized and, rapid and essentially continuous discharges become possible by switching the connection between the lamp and the condensers so that the lamp is connected to a charged condenser.

Second, an instantaneous and intermittent flash of the flash lamp prevents super heating of the heat sensitive paper.

What is claimed is:

1. In a heat sensitive copying device including a flash lamp for providing the heat to cause the copying of an image on heat sensitive copy paper comprising:

first and second condensers;

switch means coupled between the flash lamp and said condensers for alternately coupling one of said condensers to the flash lamp while coupling the other condenser to a charge circuit;

bistable circuit means for operating said switch means;

first relay means;

second relay means for toggling said bistable circuit means and energizing said first relay means;

contact means responsive to the energization of said first relay means for triggering said flash lamp;

a cushion plate for receiving the heat sensitive copy paper and an image bearing original; and

a transparent pressing plate for forcing the image bearing original and copy paper into operable contact;

wherein said flash lamp can be readily connected to a charged condenser to cause rapid, successive lightings of the lamp due to the alternate coupling of one of said condensers to the flash lamp while coupling the other condenser to a charging circuit. 

1. In a heat sensitive copying device including a flash lamp for providing the heat to cause the copying of an image on heat sensitive copy paper comprising: first and second condensers; switch means coupled between the flash lamp and said condensers for alternately coupling one of said condensers to the flash lamp while coupling the other condenser to a charge circuit; bistable circuit means for operating said switch means; first relay means; second relay means for toggling said bistable circuit means and energizing said first relay means; contact means responsive to the energization of said first relay means for triggering said flash lamp; a cushion plate for receiving the heat sensitive copy paper and an image bearing original; and a transparent pressing plate for forcing the image bearing original and copy paper into operable contact; wherein said flash lamp can be readily connected to a charged condenser to cause rapid, successive lightings of the lamp due to the alternate coupling of one of said condensers to the flash lamp while coupling the other condenser to a charging circuit. 